In order to meet the rapid increase in demand for mobile data, the wireless communication system has evolved over and over again and current representative communication system is Long Term Evolution (LTE) system.
In the LTE system, when it has data to be transmitted in uplink buffer, the terminal notifies base station of the current buffer state by transmitting a Buffer Status Report (BSR). Meanwhile, there is a need of defining the operation to be performed depending on whether the BSR is a normal BSR, periodic BSR, or BSR transmitted using the padding resource remained after base station's scheduling.